1. Field of the Invention
This invention relates to a fluid injection nozzle. For example, this invention relates to the injection nozzle of an electromagnetic fuel injection valve for supplying fuel to an internal combustion engine for automotive use by means of injection.
2. Description of the Related Art
A conventional fluid injection nozzle is the one provided with a plurality of plates overlaid on one another and formed of silicone having orifices on the front of the injection hole thereof, wherein for example, the plates having a plurality of slit-shaped orifices are overlappingly arranged on their downstream side surfaces so that at least parts of the respective orifices communicate with one another and by supplying fuel to these orifices through the injection hole, fuel atomized and spread in a wide angle is injected to a plurality of directions.
The fluid injection nozzle mentioned above is illustrated in the FIGS. 12 and 13. The sheet part 100a of a needle 100 is formed so as to be brought into contact with the valve seat 101a of a needle body 101. First and second orifice plates 110 and 112 are provided on the fuel downstream side of the injection hole 101b of the needle body 101. The second orifice plate 112 is overlaid on the under surface of the first orifice plate 110. A sleeve 102 is fittingly inserted with pressure into the needle body 101 and thereby the first orifice plate 110 is fixed on the end face 101c of the needle body 101.
The first orifice plate 110 comprises a first tapered orifice 111 toward a slit-shaped fuel downstream side while the second orifice plate 112 comprises two second tapered orifices 113 and 114 toward the fuel downstream side. Here, the term "tapered" means that a cross-sectional area is gradually reduced from the fuel upstream side to the fuel downstream side. The second orifice 113 comprises square-like apertures 113a and 113b on the fuel upstream and downstream sides and the apertures 113a and 113b are concentrically formed. Also, the second orifice 114 comprises square-like apertures 114a and 114b on the fuel upstream and downstream sides and the apertures 114a and 114b are concentrically formed.
At the fluid injection nozzle shown in the FIGS. 12 and 13, the second orifices 113 and 114 are arranged on the downstream side of the first orifice 111 and thereby, dual-oriented spaying is obtained. Further, the direction of dual-oriented spraying can be adjusted by changing a space between the second orifices 113 and 114.
At the fluid injection nozzle shown in the FIGS. 12 and 13, however, the predetermined direction of spaying cannot be obtained when shifts in the positions of the first orifice 111 and the second orifices 113 and 114 is occurred. Further, in the case where an orifice is made of silicone, the direction of spaying cannot be adjusted by changing the tilt angle of the orifice, since etching is possible only at the same tilt angle.